NARRATOR

Today, Tuesday, December 7, 2021, the U.S. Space Force’s Space Test Program Satellite-6 launched from Kennedy Space Center on Florida’s space coast. The spacecraft ascended to orbit in the faring of a United Launch Alliance Atlas V rocket. The spacecraft contains — among other things — a revolutionary space communications demonstration, the culmination of decades of research and technology investments in optical communications: the Laser Communications Relay Demonstration, or LCRD.

I’m Danny Baird. This is “The Invisible Network.” In this first episode of a five-part series about LCRD, NASA’s latest optical communications demo, we’ll overview the basics of the mission and set the stage for this bold technology development effort.

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TRUDY KORTES

My name is Trudy Kortes and I’m the program director for technology demonstrations within the Space Technology Mission Directorate at NASA Headquarters… it’s about a $500 million a year program… We develop a broad range of technologies — oh, gosh — in advanced propulsion, power, communications — obviously, like we’re talking about today — advanced navigation, entry, descent, landing, orbital servicing, and just many others.

NARRATOR

The Space Technology Mission Directorate — or STMD as it’s known within the agency — is one of the key players in the development of LCRD. They worked alongside the Human Exploration and Operations Mission Directorate‘s Space Communications and Navigation program, or SCaN, to develop and launch the LCRD payload.

TRUDY KORTES

There have been there been, you know, laser or optical communications types of missions or demonstrations going on since the mid 90s… With LCRD, we’re taking another step… to create kind of an interoperable and resilient, you know, space and ground communication and navigation infrastructure… If you really think about it, radio frequency — of course — is the standard. But we will get to a point one day where there will be options: which is, what does this particular mission need? Does it need just RF? Does it need just optical? Or does it need a combination of both?

NARRATOR

Radio communications technologies have been integral to NASA’s success since the agency’s earliest days. Videos of humankind’s first steps on the Moon flowed over radio waves. The Hubble Space Telescope, the International Space Station, and the Space Shuttle have all relied on radio. Though these technologies are time-tested, optical communications — or simply laser comm — has a host of benefits that could supplement existing radio systems to offer huge benefits to missions.

DAVE ISRAEL

I’m Dave Israel at the NASA Goddard Space Flight Center. I am the division architect for the Exploration and Space Communications projects division and I’m also the principal investigator for the Laser Communications Relay Demonstration.

So, the optical links. The first thing that comes to people’s mind is higher data rates… So, moving to optical… brings the potential for higher data rates. One of the other benefits that’s very significant for space missions, is that at the same data rate, for an optical link, you can have much smaller equipment. So instead of larger antennas — higher power amplifiers for radio frequency or RF systems — you can have smaller telescopes and smaller laser power, and you can really shrink it down.

NARRATOR

So essentially, there are two main benefits of the optical communications technologies demonstrated by LCRD. The first is that laser links can support higher data rates than radio transmissions. Higher data rates means more data can be transmitted in the same amount of time. More data means more precise instruments and high definition video, leading to greater science and exploration returns.

The second advantage is that optical telescopes have reduced size, weight, and power requirements when compared to radio systems. A smaller size means more room for science instruments. Less weight means a less expensive launch. Less power means less drain on the spacecraft’s batteries.

How does optical communications accomplish these feats? For that, we turn to LCRD co-investigator Bernie Edwards.

BERNIE EDWARDS

I am the chief communication system engineer at Goddard Space Flight Center… Specifically, over the last 10 years probably, I’ve been involved in new technology development, so: what are better ways for spacecraft to communicate with Earth?

NARRATOR

Optical communications uses infrared lasers as opposed to radio waves to communicate, moving the frequency to just below that of visible light. While that may seem like a huge difference, Edwards explains that not all is as it seems.

BERNIE EDWARDS

Radio waves and light… they’re both electromagnetic waves. And so basically, the laser or the light is: imagine packing more these waves tighter and tighter and tighter. So because of that we can transmit more information.

NARRATOR

The higher frequency of infrared lasers, which are invisible to humans, allows NASA to squeeze more data per second onto a single transmission when compared to radio. The laser light used in optical communications is also more focused than radio, which spreads out a lot more as it travels through space:

BERNIE EDWARDS

If you’re at Mars, and then you transmit back, typically using a radio wave… because it spreads out as it goes through space, by the time it gets back to the Earth, it might be 10-, 15-, 20-times the size of the Earth’s diameter. And you say that’s great, because that means I can hit the planet, which is true. But the problem is, if you want to collect all that energy, right — you want to be very efficient with your energy so you can transmit more data — then you’d have to have a radio antenna 10-, 15-, 20-times the size of the Earth. So that’s obviously unrealistic.

Now, if we go to optical communications — so as we all have experience in our day-to-day lives with, like, laser pointers — that beam is very tight.

NARRATOR

While the energy from an optical transmission still spreads out, it is significantly more focused than radio. An optical ground station can collect more energy of a laser transmission, leading to more efficient communications.

These benefits are just some of the many ways that optical communications will enhance data transmission. The LCRD mission is a collaborative effort that serves as the next step in making these capabilities operational realities.

BERNIE EDWARDS

For LCRD, we have a strong partnership across the country. The flight payload was built, integrated and tested at Goddard Space Flight Center, with support from MIT Lincoln Laboratory. And then we have a partnership with the Jet Propulsion Laboratory.

NARRATOR

John Moores from the Massachusetts Institute of Technology Lincoln Laboratory, a federally funded research and development center, serves as another co-investigator on the mission.

JOHN MOORES

I was actually involved in composing the proposal for the program back around the 2011 timeframe… and I’ve been with the project for almost a decade now.

NARRATOR

Like the other investigators, he has an extensive background in optical communications, but he still sees LCRD as a unique opportunity:

JOHN MOORES

So, there’s been a lot of laser comm demonstrations… I would say that a lot of the prior demonstrations have been sort of one-off demonstrations — you know, someone did the experiment and got the data, published it, did their press release, and moved on — whereas LCRD is really all about demonstrating reliable, consistent operations over a long period of time…

We’ll be looking at the atmospheric physics. When you send a laser beam through the Earth’s atmosphere, it gets distorted in various ways, but we have a lot of clever ways to overcome the effects of the atmosphere. And so, we’ll be looking at how effective those are…

We’ll also get to look at things like network protocols… How you design your signal waveforms, and how you multiplex different data streams together, and what do you do when there’s an outage, how do you preserve the data and then send it at the right time. Those sorts of things will be interesting to look at as well.

NARRATOR

And that’s what we’ll learn about in the next episode of this season. We’re going to learn about the legacy of optical communications missions at NASA, the origins of LCRD itself, and about the goals of the mission overall. Later in the season, we’ll talk about the design of the mission’s flight and ground segments. We’ll also peer into the future of optical communications: from LCRD’s use as a data relay for the International Space Station, to exciting upcoming optical missions to the Moon and deep space.

Stay tuned for a journey where lasers light the way.

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NARRATOR

Thank you for listening. Do you want to connect with us? The Invisible Network team is collecting questions about laser communications from listeners like you! We’re putting together a panel of NASA experts from across the Space Communications and Navigation community to answer your questions.

If you would like to participate, navigate over to NASA SCaN on Twitter or Facebook and ask your question using the hashtag AskSCaN. That’s @ NASA SCaN, N-A-S-A-S-C-A-N, on social media, with the hashtag AskSCaN, A-S-K-S-C-A-N.

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This LCRD-focused season of “The Invisible Network” debuted after the launch of the U.S. Space Force’s Space Test Program Satellite-6 on Dec. 7, 2021. LCRD is led by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in partnership with NASA’s Jet Propulsion Laboratory in Southern California and the MIT Lincoln Laboratory. LCRD is funded through NASA’s Technology Demonstration Missions program, part of the Space Technology Mission Directorate, and the Space Communications and Navigation (SCaN) program at NASA Headquarters in Washington, D.C.

The podcast is produced by SCaN at Goddard with episodes written and recorded by me, Danny Baird. Editorial support provided by Katherine Schauer. Our public affairs officers are Lora Bleacher, Kathryn Hambleton, and Clare Skelly of the Space Technology Mission Directorate.

Special thanks to Barbara Adde, SCaN Policy and Strategic Communications director, and all those who have lent their time, talent and expertise to making “The Invisible Network” a reality. Be sure to rate, review, and follow the show wherever you get your podcasts. For transcripts of the episodes, visit NASA.gov/invisible. To learn more about the vital role that space communications plays in NASA’s mission, visit NASA.gov/SCaN. And for more NASA podcast offerings, visit NASA.gov/podcasts.